Cambridge IGCSE™
COMPUTER SCIENCE
0478/11
Paper 1 Theory
May/June 2024
MARK SCHEME
Maximum Mark: 75
Published
This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the
examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the
details of the discussions that took place at an Examiners’ meeting before marking began, which would have
considered the acceptability of alternative answers.
Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for
Teachers.
Cambridge International will not enter into discussions about these mark schemes.
Cambridge International is publishing the mark schemes for the May/June 2024 series for most
Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some
Cambridge O Level components.
This document consists of 12 printed pages.
© Cambridge University Press & Assessment 2024
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0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Generic Marking Principles
May/June 2024
These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the
specific content of the mark scheme or generic level descriptions for a question. Each question paper and mark scheme will also comply with these
marking principles.
GENERIC MARKING PRINCIPLE 1:
Marks must be awarded in line with:
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the specific content of the mark scheme or the generic level descriptors for the question
the specific skills defined in the mark scheme or in the generic level descriptors for the question
the standard of response required by a candidate as exemplified by the standardisation scripts.
GENERIC MARKING PRINCIPLE 2:
Marks awarded are always whole marks (not half marks, or other fractions).
GENERIC MARKING PRINCIPLE 3:
Marks must be awarded positively:
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marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond
the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate
marks are awarded when candidates clearly demonstrate what they know and can do
marks are not deducted for errors
marks are not deducted for omissions
answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the
question as indicated by the mark scheme. The meaning, however, should be unambiguous.
GENERIC MARKING PRINCIPLE 4:
Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level
descriptors.
© Cambridge University Press & Assessment 2024
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0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
May/June 2024
GENERIC MARKING PRINCIPLE 5:
Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may
be limited according to the quality of the candidate responses seen).
GENERIC MARKING PRINCIPLE 6:
Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or
grade descriptors in mind.
Mark scheme abbreviations:
/
//
Underline
max
()
separates alternative words / phrases within a marking point
separates alternative answers within a marking point
actual word given must be used by candidate (grammatical variants accepted)
indicates the maximum number of marks that can be awarded
the word / phrase in brackets is not required, but sets the context
Note: No marks are awarded for using brand names of software packages or hardware.
© Cambridge University Press & Assessment 2024
Page 3 of 12
0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
1(a)
Answer
May/June 2024
Marks
2
Any two from:
Example:
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1(b)
Touch screen
Microphone
Button
Webcam // (digital) camera
Accelerometer
Biometric device
Any one from:
1
Example:
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1(c)
Screen
Speaker
LED
SSD // Solid-state drive // Solid-state (device)
© Cambridge University Press & Assessment 2024
1
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0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
Answer
May/June 2024
Marks
2(a)
C
1
2(b)
14
20
A5
3
Question
Answer
Marks
3(a)
00011000
1
3(b)
D
1
3(c)
One mark for correct working
2
Example: Flip and add
One mark for correct answer: −93
3(d)
1024
Question
4(a)
Answer
Any three from:
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4(b)
1
Marks
3
A packet is split into three different sections
… the header
… the payload
… the trailer
Router
© Cambridge University Press & Assessment 2024
1
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0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
4(c)
Answer
Marks
3
Any three from:
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May/June 2024
The network may be spread over a long distance …
… so it is more reliable
Bits will be sent/arrive in sequence
…so bits less likely to be skewed
Less crosstalk/interference
… so less likely to have errors
The data may not need to be transmitted at a fast speed // data transmission speed of serial is adequate
The cables in the network only use serial transmission
Question
Answer
Marks
5(a)
To store data/files/software permanently
1
5(b)
Compact disk (CD)
Digital versatile disk (DVD)
Blu-ray disk
3
5(c)
Any three from:
3
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To store data temporarily
To store data currently in use
To store software currently in use
Data can be accessed faster (than secondary storage)
To speed up the fetch stage (of the fetch-execute cycle)
© Cambridge University Press & Assessment 2024
Page 6 of 12
0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
5(d)
Answer
The diagram shows:
The registers MAR, MDR and PC
Address sent from PC to MAR
…using address bus (award anywhere for correct use of address bus)
…PC is incremented
Address sent from MAR to RAM
Data/instruction sent from RAM to MDR
…using data bus (award anywhere for correct use of data bus)
Data/instruction sent from MDR to CIR/CU
Control unit sending control signal for any part of the process
… using control bus (award anywhere for correct use of control bus)
Example:
PC sends address to
MAR then increments
Control
unit
Marks
4
Any four from:
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May/June 2024
PC
The address is sent
from the MAR using
the address bus
RAM
MAR
CIR
MDR
The instruction is
sent to the CIR to be
decoded
© Cambridge University Press & Assessment 2024
The instruction is
sent to the MDR
using the data bus
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0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
6(a)
Answer
6(b)
Marks
1
Any one from:
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May/June 2024
Permanently store instructions (in ROM)
Stores instructions to boot up/start up the computer
Provides the operating system with a platform to run on
Controls/manages/allows communication with hardware
Store instructions securely (to stop them being easily corrupted)
Any one from:
1
Example:
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6(c)
Bootstrap
Bootloader
BIOS
Operating system (in embedded system)
Programs (in embedded systems)
Any two from:
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2
Operating system
Utility software
NOTE: Two examples of utility software can be awarded
Question
7
Answer
One mark for each correct term in the correct place.
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4
plain text
cipher text
public key
private key
© Cambridge University Press & Assessment 2024
Marks
Page 8 of 12
0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
Answer
May/June 2024
Marks
8(a)
The robot can perform actions without human intervention
1
8(b)
Any three from:
3
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8(c)
6
Any six from:
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8(d)
It has a mechanical structure/framework
It has electrical components
It is programmable
It can move
A proximity sensor is used
The sensor continuously sends digitised data to the microprocessor
The microprocessor compares the data to a stored value/range of values
If the value is within the range/matches the robot continues planting
If the value is above/below/outside the range a signal is sent by the microprocessor to turn/stop the robot
… using an actuator to turn/stop the robot
This process repeats until the robot is turned off
Any two from:
2
Example:
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The robot is more accurate when planting seeds
The robot does not need to take breaks // works 24/7
The robot will not get bored of performing a repetitive task
The farmer can perform other tasks whilst the robot is planting the seeds
The robot may be faster/more efficient (at planting seeds)
Safer as the robot can work in a more dangerous environments (e.g. with animals in a field)
Doesn’t need to pay labour costs/wages
© Cambridge University Press & Assessment 2024
Page 9 of 12
0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
8(e)
Answer
May/June 2024
Marks
2
Any two from:
Example:
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8(f)
The robot may have been expensive to purchase
The robot may need maintenance and this may be costly
The robot may take away jobs from humans that previously planted the seeds
Farmer/workers may be deskilled
Farmer may need training in how to use the robot
If it breaks the farmer will need to manually plant
If faulty it may cause damage to farm/seeds
Cannot adapt to a new/unexpected event
Any two from:
2
Example:
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9(a)
The robot can now adapt itself by changing its own rules/data/ processes
The robot will become more efficient
… as it has a greater knowledge of its surroundings/environment
… as it can remember where a fence is
… as it can remember the route it needs to take
… as it can remember where any obstacles are to avoid
… as it can remember where to start and stop sowing seeds
… as it may make fewer errors
Any three from:
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3
Data could be lost
Data could be gained/added
Data could be changed
Bits could be reassembled in the wrong order
Interference could occur
Crosstalk could occur
Data collisions could occur
Data packets could time out/reach their hop count
Network could be infected with malware
© Cambridge University Press & Assessment 2024
Page 10 of 12
0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
9(b)(i)
9(b)(ii)
Answer
9(c)(i)
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The 1s are counted (in each byte)
Each byte has a parity bit
If the number of 1s are odd the parity bit is 0 (otherwise it is 1)
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(The first packet of) data is sent and a timer is started
The receiving device counts the number of 1s (in each byte)
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If the number of 1s are odd/data meets odd parity an acknowledgement is sent to say the data is error free …
… the sender then sends the next packet of data …
… and the timer is restarted
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If the number of 1s is even an acknowledgement is not sent
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If no acknowledgement is received within a set timeframe/before timeout …
… the data packet is resent
Any two from:
2
Echo check
Checksum
Even parity check
Negative ARQ
Any five from:
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Marks
8
Any eight from:
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May/June 2024
5
Criteria can be set (for traffic)
… such as a blacklist/whitelist (of IP addresses)
It will examine traffic coming into the network
It will check that the traffic meets the set criteria
… and will reject it if it does not meet criteria
Certain ports used by hackers can be blocked/closed
© Cambridge University Press & Assessment 2024
Page 11 of 12
0478/11
Cambridge IGCSE – Mark Scheme
PUBLISHED
Question
9(c)(ii)
Answer
Example:
Virus
Worm
Trojan horse
Spyware
Adware
Ransomware
© Cambridge University Press & Assessment 2024
Marks
2
Any two from:
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May/June 2024
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